Bidirectional intraflagellar transport is restricted to two sets of microtubule doublets in the trypanosome flagellum

Eloise Bertiaux (1, 2) , Adeline Mallet (1, 2, 3) , Cécile Fort (1, 2) , Thierry Blisnick (1) , Serge Bonnefoy (1) , Jamin Jung (1) , Moara Lemos (1) , Sergio Marco (4, 5, 6, 7) , Sue Vaughan (8) , Sylvain Trépout (4, 5, 6, 7) , Jean-Yves Tinevez (9) , Philippe Bastin (1)

1 Biologie cellulaire des Trypanosomes - Trypanosome Cell Biology
2 Cellule Pasteur UPMC
3 UTechS UBI - Plateforme BioImagerie Ultrastructurale – Ultrastructural BioImaging Platform
4 Institut Curie [Paris]
5 PSL - Université Paris Sciences et Lettres
6 INSERM - Institut National de la Santé et de la Recherche Médicale
7 CNRS - Centre National de la Recherche Scientifique
8 Oxford Brookes University
9 UTechS PBI - BioImagerie Photonique – Photonic BioImaging

Intraflagellar transport (IFT) is the rapid bidirectional movement of large protein complexes driven by kinesin and dynein motors along microtubule doublets of cilia and flagella. In this study, we used a combination of high-resolution electron and light microscopy to investigate how and where these IFT trains move within the flagellum of the protist Trypanosoma brucei Focused ion beam scanning electron microscopy (FIB-SEM) analysis of trypanosomes showed that trains are found almost exclusively along two sets of doublets (3-4 and 7-8) and distribute in two categories according to their length. High-resolution live imaging of cells expressing mNeonGreen::IFT81 or GFP::IFT52 revealed for the first time IFT trafficking on two parallel lines within the flagellum. Anterograde and retrograde IFT occurs on each of these lines. At the distal end, a large individual anterograde IFT train is converted in several smaller retrograde trains in the space of 3-4 s while remaining on the same side of the axoneme.

Domaines: Biologie cellulaire; Sciences du Vivant [q-bio]

Eloise Bertiaux, Adeline Mallet, Cécile Fort, Thierry Blisnick, Serge Bonnefoy, et al.. Bidirectional intraflagellar transport is restricted to two sets of microtubule doublets in the trypanosome flagellum. Journal of Cell Biology, 2018, ⟨10.1083/jcb.201805030⟩. ⟨pasteur-01931458⟩